He currently plays for FC Rosengard Women, wearing the number 51 shirt. At the international level, he represents Sweden Women U17. He plays primarily as a Defender.

Throughout the UEFA European U19 Women's Championship 2025-2026, Thea staffansson featured in 3 matches, averaging 0 tackles, 0 interceptions, and 0 clearances per game, while blocking 0 shots per game.